Abstract: In the multidisciplinary design optimization process of complex engineering system, the large amount of calculation and low computation efficiency resulting from various disciplines and high dimensionality of design space are critical problems to be solved. The sparse grid approach is applied to construct discipline approximate model, which includes experimental design and construction of approximate model, and it can relieve the curse of dimensionality. Also it has a high computing efficiency in solving problems of high dimensionality and has the apriority of fitting precision. Then the approximate model based on sparse grid approach is applied to solve the prediction of Haupt function and optimization design of NASA reducer, compared with the traditional ploynomial response surface and Kriging approximate model, the sparse grid approach shows high precision and efficiency in solving high dimensionality problems and feasibility in design optimization. A multidisciplinary design optimization flow model using sparse grid approach is constructed, based on which the lightweight design of driving axle housing is implemented, and the results show all the design schemes reduced mass of driving axle housing with little change in modal frequencies as well as met criteria of driving axle strength and fatigue life.

Key words: Approximate model, Lightweight design, Multidisciplinary design optimization, Sparse grid approach